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AF540FGZ II Auto Flash

Dustproof & weather-resistant P-TTL Auto Flash Wireless High-speed sync Auto zoom Contrast-control sync

With a maximum guide number of 54 (at ISO100/m), this high-capacity, clip-on auto flash features a dustproof, weather-resistant structure to deliver dependable performance even under demanding outdoor conditions, such as at dusty locations and in the rain. Since it features a powerful white-LED flash head and an AF-assist light for shooting in the dark, it can be used not only for close-range movie recording, but also for still-image shooting with extended exposures. It provides nine custom functions to personalize its operation, including on/off switching of the LED light when used as a catch light, and setting of the LED light’s discharge mode in still-image shooting.

LCD control panel
in backlight mode

This auto flash features a dustproof, weather-resistant structure identical to that of the camera body, with 28 sealing parts applied across the unit, including the hot shoe. Its power switch, control dials and buttons, and battery compartment are all completely sealed to provide an airtight structure. It even has a tightening knob to eliminate gaps between its hot shoe and the camera’s contacts. A light twist of this knob assures solid connection of the electrical contacts, while preventing the intrusion of foreign substances.

Flash Specifications
(for APS-C-format SLR cameras)

P-TTL Auto Available
auto flash
Manual guide number
[ISO100 • m]
21(13mm) , 32(16mm) , 35(19mm) , 39(24mm) , 45(34mm) , 50(48mm) , 54(58mm)
Manual guide number
[ISO200 • m]
30(13mm) , 45(16mm) , 49(19mm) , 55(24mm) , 64(34mm) , 71(48mm) , 76(58mm)
Discharge angle Discharge angle adjustable at six settings with automatic or manual zooming of flash head
Angle-of-view coverage of 16mm, 19mm, 24mm, 34mm, 48mm and 58mm
Wide-angle panel
Angle-of-view coverage of a 13mm lens
Bounce flash Up(~90°) , Down(~10°) , Left(~135°) , Left(~180°)
Discharge level
-4.0EV ~ +2.0EV (in 1/3EV or 1/2EV steps) *
AF-assist light Available **
Size and weight
76mm(W) x 113mm(H) x 108mm(D)
350g (flash body only)
Power source Four AA-cell batteries
Other functions • Exclusive use with digital SLR cameras
• Dustproof, weather-resistant structure
• Automatic camera-format switching
• Customization with nine custom functions
• Wireless sync mode
• High-speed sync mode

* The discharge level is also adjustable on the camera body.
** For use with 645D, K-5 II, K-5 IIs, K-5, K-30, K-50 or K-r camera bodies, the camera’s firmware must be updated to the latest version.

Wireless P-TTL Auto Flash


This advanced flash mode is available by mounting the AF540FGZ II or AF360FGZ II Auto Flash unit on a K- or *istD-series camera body. Using the camera-mounted flash unit as a master unit or controller, it enables highly accurate, wireless operation of advanced P-TTL Auto Flash applications.

*Cameras compatible with wireless P-TTL Auto Flash operation using the camera’s built-in flash:
KP/K-3/K-50/K-30/K-5II/K-5IIs/K-5/K-7/K-r/K-x/K-m/K20D/K200D/K10D FW Ver.1.10 or later/K100D Super


The linked page shows a list of frequently asked questions and corresponding answers for the Auto-flash PENTAX AF540FGZII/AF360FGZII.

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